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    <title>Document</title>
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        span{
            color: blue;
            background: #ccc;
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<body>
    <p>Web</p>
    <!-- 2.行内样式 -->
    <div style="color: green; font-size: 30px;">Java</div>
    <span>Android</span>
    <p>IOS</p>
    <div>哈哈</div>
    <h2>嘿嘿</h2>
</body>
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